题目大意 #!/usr/bin/env python # coding=utf-8 # Date: 2018-08-30 """ https://leetcode.com/problems/symmetric-tree/description/ 101. Symmetric Tree Given a binary tree, check whether it is a mirror of itself (ie, symmetric around its center). Fo…

  思路: 主要判断左子树与右子树. 在判断左时,循环下去肯定会到达叶子结点中最左边的结点与最右边的结点比较. 到了这一步因为他们都没有左(右)子树了,所以得开始判断这两个结点的右(左)子树了. 当某个结点对称了,它的左子树也对称了,右子树也对称了,那才是真的对称了. C++ /** * Definition for binary tree * struct TreeNode { * int val; * TreeNode *left; * TreeNode *right; * TreeNode…

Given a binary tree, check whether it is a mirror of itself (ie, symmetric around its center). For example, this binary tree [1,2,2,3,4,4,3] is symmetric: 1 / \ 2 2 / \ / \ 3 4 4 3 But the following [1,2,2,null,3,null,3] is not: 1 / \ 2 2 \ \ 3 3 Not…

Given a binary tree, check whether it is a mirror of itself (ie, symmetric around its center). For example, this binary tree is symmetric: 1 / \ 2 2 / \ / \ 3 4 4 3 But the following is not: 1 / \ 2 2 \ \ 3 3 Note:Bonus points if you could solve it b…

这道题是LeetCode里的第101道题.是我在学数据结构——二叉树的时候碰见的题. 题目如下: 给定一个二叉树,检查它是否是镜像对称的. 例如,二叉树 [1,2,2,3,4,4,3] 是对称的. 1 / \ 2 2 / \ / \ 3 4 4 3 但是下面这个 [1,2,2,null,3,null,3] 则不是镜像对称的: 1 / \ 2 2 \ \ 3 3 说明: 你可以运用递归和迭代两种方法解决这个问题. 解题思路: 读完题目后我首先想到的是用遍历的方法来解题,树的遍历有三种:前序遍历,中…

Given a binary tree, check whether it is a mirror of itself (ie, symmetric around its center). For example, this binary tree [1,2,2,3,4,4,3] is symmetric: 1 / \ 2 2 / \ / \ 3 4 4 3 But the following [1,2,2,null,3,null,3] is not: 1 / \ 2 2 \ \ 3 3 Not…

题目:Symmetric Tree <span style="font-size:18px;"><span style="font-size:18px;">/**LeetCode Symmetric Tree 对称的树 * 思路:推断一棵树是否对称,1.有左子树就要有右子树 * 2.除根节点外对称节点值要同样 * 注意:对称后就是左子树的左节点和右子树的右节点比較 * Definition for binary tree * public c…

判断一棵二叉树是否为对称的树.如 1 / \ 2 2 / \ / \ 3 4 4 3 观察上面的树可以看出:左子树的右子树等于右子树的左子树,左子树的左子树等于右子树的右子树. 首先可以使用递归.递归容易理解 class Solution { public boolean isSymmetric(TreeNode root) { if(root==null) return true; return isSym(root.left,root.right); } public boolean isS…

Symmetric Tree Given a binary tree, check whether it is a mirror of itself (ie, symmetric around its center). For example, this binary tree is symmetric: 1 / \ 2 2 / \ / \ 3 4 4 3 But the following is not: 1 / \ 2 2 \ \ 3 3 Note:Bonus points if you c…

判断一棵树是否自对称 可以回忆我们做过的Leetcode 100 Same Tree 二叉树和Leetcode 226 Invert Binary Tree 二叉树 先可以将左子树进行Invert Binary Tree,然后用Same Tree比较左右子树 而我的做法是改下Same Tree的函数,改动的是第27行 /** * Definition for a binary tree node. * struct TreeNode { * int val; * TreeNode *left;…